2002 Explorer problem

I have an '02 Explorer with 100,000 miles. I'm not mechanical and so need help with possible reasons for an issue it's having. When I start it in the morning, it seems to have a slight problem getting going as if the fuel isn't getting in. Once it's running it is mostly fine. However, I've noticed that sometimes as I'm accelerating I get the same sort of feel. It was particularly noticeable yesterday when I was going about 50 mph and starting up a hill.

Would this be a possible sign of a clogged fuel filter or injectors?

Just had the transmission flushed and new spark plugs and PCV valve put in, but not sure if that is related. The problem seemed to start occurring after this work was done, although, I could just be noticing every little noise and bump now more than before.

Welcome to the forum!

It almost sounds as if you may have a misfire. Basically, a misfire is a cylinder that is not contributing for some reason (lack of spark, lack of fuel, lack of air) and would give the impression of decreased power. Typically this will also be felt as roughness in the way the engine is running at low engine speed. Since you mention that you just had spark plugs changed, maybe a plug wire did not get seated fully. I don't recall if the 2002 Explorer uses Coil-on-Plug (CoP) or still has spark plug wires for the V6. The V8 uses CoP.

It could also be a fuel related issue as you suggest. If you have not replaced the fuel filter and/or used fuel injector cleaner additive in your fuel tank, that would be a good investment as that is part of your routine maintenance schedule anyway.

Also consider the fuel you're using. Did this just start happening following a tank full of fuel?

-Rod

I'm sure the fuel filter was replaced at 90,000 and I think the injection system was flushed out as well (have to re-check my service records on that one). I did read somewhere in my research that as injecters age, they don't work as efficiently and it might be a good idea to replace them around the 80,000 mile mark. That info wasn't specific for Explorers, so I wasn't sure if it applied.

I may have the mechanic double check the spark plugs as you suggest since the very next day after they were put in is when I noticed the very obvious difference in how my SUV drove. That shouldn't take long to do should it? Could I do that myself? Would it make a difference if my SUV used Coil-on-Plug (CoP) or spark plug wires? Are CoP different when it comes to getting the spark plugs seated correctly?

Told you I wasn't much of a mechanic beyond changing air filters, checking oil, etc. :)

The seating of the spark plugs won't be different between the CoP system and older system with spark plug wires. The difference is with the CoP system, there is less chance that a spark plug wire is not seated correctly. Plug wires "snap" on to the spark plugs. The CoP coils just rest on the spark plug and rely on a spring to make good contact with the plug. The coil is then bolted to the head to maintain a good connection.

If you have the V6, I'd suspect that one of the spark plug wires is loose, either at a spark plug or at the coil.

-Rod

I am having the exact same problem - loss of power at times, problems accelerating, etc.. I just had the battery and spark plugs changed. I am wondering if it could in any way be related to the transmission problems that others are experiencing? Is that possible? (Keep in mind I know nothing about vehicles)...

Update:

Initially, I had the tune-up done at the dealership. After reading here the suggested reason for my problem, I took the Ex to another mechanic who test drove with me and confirmed the misfire.

I went back to the dealer and told them I had a misfire. I think they were shocked that I used the correct terminology! They popped the hood, jiggled the wires (I don't have CoP), replaced one they thought was defective (the wires are the original), and told me that should fix it.

That eliminated the majority of the problem, but I would periodically get the misfire so I went back to the independent mechanic. We replaced all the wires and he checked the plugs. Two were cracked! Plus, according to his specs, the dealer had put in the wrong plugs (different part number).

I'm taking the cracked plugs back to show the dealer and try to get some money back. I shouldn't have to pay twice to get a job done right. Afterall, I gave them the opportunity to fix it. Geez, all for a simple tune-up.

The definite misfire appears to be gone, but here's a question. I sense a little engine rumbling that wasn't there before. It's not teeth-rattling, but it doesn't run quite as smoothly as I'm sure it did before. Does something need aditional adjustment?

Thanks for all the help.

Be careful with how you approach the dealer. From your description, it sounds like they just replaced a wire, not the spark plugs. A full tune-up, including new spark plugs and wires, would be quite pricey. The way I see it, they attempted to help you out by only replacing what they thought you needed to solve the issue you brought it to them for. Did you ask them to check the spark plugs and spark plug wires?

Also, from the factory, the Explorer will have a different spark plug number on each side of the coil. This is due to the coil circuit. One coil is used to fire two cylinders and the coil is basically a center tapped transformer, so the two plugs are conceptually opposite polarity. For maximum efficiency, the factory uses a different plug. However, the manufacturer does not require that you use the different plugs when replacing them.

I suspect what your independent mechanic found was two different plug part numbers and didn't understand that this is how the vehicle comes off the assembly line.

As for the new roughness, you may want to have your independent mechanice double check his work and make sure he didn't leave a plug wire not quite seated, or that he didn't knock a vacuum hose off in the process of changing the plugs and wires.

-Rod

Be careful with how you approach the dealer. From your description, it sounds like they just replaced a wire, not the spark plugs. A full tune-up, including new spark plugs and wires, would be quite pricey. The way I see it, they attempted to help you out by only replacing what they thought you needed to solve the issue you brought it to them for. Did you ask them to check the spark plugs and spark plug wires?

The thing is, though, I wasn't having any problems until the dealer replaced the spark plugs in the first place as my maintenance info says to do at 100,000 (only spark plugs and pcv valve-no wires) I had actually just taken the Explorer in for an oil change when they informed me that the spark plugs needed changing. The misfire started occurring the next day and I took it back to them after I realized what was happening. That's when they replaced the one wire. They did not check the spark plugs. I even asked them if perhaps one of the spark plugs was bad. When I asked that, I was careful not to imply that it was their fault, but that perhaps the spark plug was just that way out of the box. Seeing as how 2 of them were cracked, though, I would guess that it happened when they put them in, either by twisting them too hard or using a tool at the wrong angle. The independent mechanic who checked the plugs wasn't going to at first because he never guessed either that the dealer cracked them putting them in.

And this certainly has gotten pricey. Everyone makes mistakes, but I gave the dealership a chance to correct it and they didn't bother to take much time to do that. If they had, a lot of hassle and expense on my part could have been avoided.

Ahhh, sorry, I missed the part in yoru first post where you mentined the issue seemed to occur following the spark plug install.

With the number of miles you have on your Explorer, you probably should have the spark plug wires replaced as well. One or more of the wires could have been damaged in the process of disconnecting the old plug wires.

One thing you may want to suggest is asking the dealer to check for misfires. They may ask you if the Check Engine Light (CEL) has ever come on and tell you if it hasn't, it isn't worth checking for a misfire. However, the Fords have a misfire monitor that can record misfires per cylinder, even if the number of misfires is not high enough to cause a CEL. These can be accessed as a Component Parameter or PID.

-Rod